This video isn't loading on my end, so I don't know exactly what you are referring to. However, I can say that I know a LOT of force free trainers who call a human and their dogs a "pack" meaning a family. That doesn't mean they believe in the dominance theory and aversive based training techniques. As for "leader", it is important to be your dogs leader- a leader who is gentle and takes care of them but does not push them around. It doesn't mean you have to be the alpha.
I know that was a shortwinded reply, but I hope it made sense.